Stock Incentive Plan (Schedule Of SSAR Exercise Price Range, Number Of Shares, Weighted Average Exercise Price And Remaining Contractual Lives) (Details) - Stock Appreciation Rights (SARs) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
SSARs Outstanding (in shares)	1,458,611	1,319,911
SSARs Exercisable, Exercisable as of December 31 (in shares)	736,201
SSARs Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 52.25
$32.01 - $43.88
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit (in dollars per share)	32.01
Range of Exercise Prices, upper limit (in dollars per share)	$ 43.88
SSARs Outstanding (in shares)	310,825
SSAR Outstanding, Weighted Average Remaining Contractual Life (Years)	5 years
SSARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 43.77
SSARs Exercisable, Exercisable as of December 31 (in shares)	78,550
SSARs Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 43.45
$47.89 - $63.64
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit (in dollars per share)	46.58
Range of Exercise Prices, upper limit (in dollars per share)	$ 63.64
SSARs Outstanding (in shares)	1,147,786
SSAR Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 8 months 12 days
SSARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 51.78
SSARs Exercisable, Exercisable as of December 31 (in shares)	657,651
SSARs Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 53.30